1. Field of the Invention
The present invention relates to a system and method for controlling mechanically-driven musical instruments, and in particular to a system and method for controlling the pedaling of a mechanically-driven piano or other instrument.
2. Background of the Technology
Beginning with the invention of pneumatically-driven reproducing pianos in the early twentieth century, systems and methods have been developed for recording music played by a human pianist and for reproducing that music on a piano. In modern reproducing pianos, music played by a human pianist may be recorded on a recording medium such as a Compact Disc or the like, and the recorded music may be recreated, for example, using actuators to drive the keys and pedals of the piano. Many reproducing pianos have attempted to reproduce the subtle pedaling effects of the original performance.
One way of controlling the pedals in a reproducing piano is described and illustrated in U.S. Pat. No. 4,450,749 to Stahnke issued May 29, 1984, which is hereby incorporated by reference in its entirety. That method and apparatus provide in the reproduced performance a very accurate reproduction of the pedaling effects in the original performance. During the original performance, the instantaneous position of the pedal mechanism (e.g. the damper lifter tray in a grand piano, or the actuator bar in a vertical piano) is sensed and recorded. At a later time when the performance is reproduced, the actuator positions the pedal mechanism in such a way that the dampers are positioned in substantially the same way they were positioned during the original performance. This method of “position pedaling” gives excellent results, but a very high price, because it requires a linear potentiometer and very accurate adjustments. The output signal from such a linear potentiometer is a linear function of the actual or achieved position of the pedal mechanism itself.
Position pedaling using a linear potentiometer requires costly hardware. In addition, installing and adjusting a mechanism including a linear potentiometer is difficult and may require specialized tools. These defects are particularly problematic for so-called “piano kits,” which include electrical and mechanical parts that are designed to be retrofitted into existing pianos. Ideally, piano kits should be easy to install, because the kits may be fitted into the pianos by technicians having a wide range of skills and tools.
One approach designed to reduce cost and simplify installation is described in U.S. Pat. No. 5,016,513 to Stahnke issued May 21, 1991, which is incorporated herein by reference in its entirety. That method and apparatus provide an approximation to pedaling effects that is relatively cost effective and easy to install. However, that approach suffers from decreased accuracy in the pedaling effects.
There is an unmet need in the art for a pedal assembly that provides accurate reproduction of pedaling effects at reduced cost. There is a further unmet need in the art for a pedal assembly that provides accurate reproduction of pedaling effects, while allowing for simpler installation.